- Preheat oven to 325°F.
- butter one 9x13 inch baking dish.
- Bring a large pot of salted water to a boil.
- Add potatoes and until tender but still firm, about 15 minutes.
- Drain, cool and ¼ inch thick.
- Place bacon in a large, deep skillet.
- Cook over high heat until lightly brown.
- Drain, chop and set aside.
- Combine the potatoes, cheese, onion, mayonnaise and salt and mix well and pour into prepared baking dish.
- Top with bacon and, and bake at 325°F for 1 hour.